Chapter 1/2 - Forces and motion Flashcards
(42 cards)
What was Newton’s first law?
That a body will remain in its present state of motion unless an external force acts upon it
What is Newton’s second law?
That force= mass x acceleration
This can be rearranged to a= f/m
It shows if the force increases so does the acceleration
What is Newton’s third law?
That every force has an equal and opposite reaction
What is the equation for speed? What is another one for the final velocity(for velocity/ speed)?
S = d/t V= u + at V2= u2 + 2as
What is the Earths gravity?
10 (9.81) m/s
What do all the parts in SUVAT mean?
S = distance / displacement U = initial velocity V = final velocity A = acceleration T = Time
What is the equation for acceleration?
A = (v-u)/t
In a distance time graph what does a horizontal line represent? What about a diagonal straight line?
In a distance time graph a horizontal line is when the object is stationary. A straight diagonal line is when the object is travelling at a constant speed.
In a distance time graph what does the gradient show?
The speed the object is moving
In a velocity time graph what does a horizontal line mean? What about a diagonal line?
In a velocity time graph a horizontal line shows the object moving at a constant speed. A diagonal line shows the object is accelerating
Give 3 equations to show the distance traveled
D= s x t S= ut + 1/2 at2 S= 1/2(u+v)t
What is acceleration?
The rate of change of velocity
What are the 2 types of velocity? Which does gravity effect?
Vertical and horizontal velocity, gravity effects the vertical velocity
What is momentum? What is its equation?
Mass x velocity, it’s conserved and passed on from one object to another, it is a vector
What is a vector?
Something that has both magnitude and direction
Eg 5 miles North, 30m/s East
What is the total momentum equation?
Total momentum before collision= total momentum after a collision
What happens to the momentum if the mass doubles?
The velocity halves
When 2 objects are pushed apart from stationary, 0ms, what is the momentum afterwards if they are both pushed away with the same force?
One would be of negative charge and the other positive so the total momentum afterwards would still be the same
What is the equation for the increase in momentum?
M x v - m x u OR m(v-u) m being mass
What is the equation for the rate of change in momentum?
m(v-u)/t
Where t is time taken for change to happen
The mass has to be involved otherwise it is the equation for acceleration
What is work done and energy transfer measured in?
Joules
What effects work done?
The force applied and the distance moved in direction of that force, such as how many books you carry in a bag and how far you travel with that effects how much energy/ force you use
What is the equation for work done?
Force applied x distance moved in direction of force
What is 1 joule of energy/ work done?
When 1 newton of force moves through one metre, if you pull a box with a steady force of 25N 3m you have done 75 Joules of work (3x75), this would have been transferred as heat and friction if it was on a rough ground
